Downhole Steerable Hammer Element

ABSTRACT

In one aspect of the present invention, a drill bit has an axis of rotation and drill bit body intermediate a threaded end and a working face. The drill bit body houses a jack element protruding from the drill bit body and the jack element has a plurality of inserts disposed on the indenting end.

BACKGROUND OF THE INVENTION

This invention relates to the field of subterranean drilling. Typically, downhole hammers are used to affect periodic mechanical impacts upon a drill bit. Through this percussion, the drill string is able to more effectively apply drilling power to the formation, thus aiding penetration into the formation.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the present invention, a drill bit has an axis of rotation and drill bit body intermediate a threaded end and a working face. The drill bit body houses a jack element protruding from the drill bit body and the jack element has a plurality of inserts disposed on the indenting end.

The plurality of inserts may be disposed primarily on one half of the indenting end. The plurality of inserts may be evenly distributed across the indenting end. The plurality of inserts may be attached to the jack element through a braze. The plurality of inserts may be attached to the jack element through a press fit. The plurality of inserts may comprise a flat ground portion, the flat ground portion disposed collinearly with an outer circumference of the jack element.

The jack element may be substantially aligned along the axis of rotation. The jack element may comprise a connection with a shaft disposed intermediate the indenting end and a gearbox. The gearbox may be in mechanical communication with a generator such that the generator powers the gearbox. The connection may be a rotating spline such that the shaft may oscillate axially within the jack element.

The shaft may be in mechanical communication with a piston, the piston circumferentially disposed around the shaft and slidably connected to the shaft. A first piston end and a second piston end may be selectively in fluid communication with a drilling mud flow such that the piston is actuated axially along the shaft according to which end of the piston is in fluid communication with the drilling mud flow. As the shaft is rotated, the jack element may also be rotated to a desired position within the drill bit through the connection. The piston may comprise a first contact surface, the first contact surface comprising a super hard material. The jack element may comprise a second contact surface, the second contact surface comprising a super hard material.

The drill bit may comprise a valve which selectively allows a drilling mud flow to contact the piston. The shaft may be substantially collinear with the axis of rotation. The plurality of inserts on the indenting end may be evenly spaced along an insert cutting profile. The insert cutting profile may comprise a pattern, the pattern comprising overlapping cutting inserts. The plurality of inserts may comprise an axis, the axis being at most 25 degrees away from parallel with the axis of rotation.

In another aspect of the present invention, a tool string component has an axis of rotation and a drill bit body intermediate a threaded end and a working face. The drill bit body houses a jack element protruding from the working face. A shaft is rotationally connected and intermediate the jack element and a torque generating device. A torque generating device is connected to a porting assembly that causes a piston to move the jack element along a central axis of the shaft and independently of the drill bit body.

The piston may comprise a friction resistant surface disposed on an inner diameter. The piston may be disposed within a substantially pressure-sealed cylinder. The pressure-sealed cylinder may comprise a first and second exhaust port such that a fluid within the pressure-sealed cylinder may be evacuated. The pressure-sealed cylinder may comprise a friction resistant surface. The shaft may comprise a friction resistant surface disposed on at least a portion of an outer diameter.

The porting assembly may comprise a first and a second rotatable disk comprising a plurality of holes which when rotated, may allow a drilling fluid to pass through the plurality of holes. The porting assembly may comprise a multi-way valve which regulates the flow of a drilling fluid. The porting assembly may be in mechanical communication with the shaft such that the porting assembly may be rotated by the shaft. The torque generating device may be a generator. The generator may comprise a signal sent to an electronic processing device disposed within the component. A position feedback sensor may be disposed within the component and in electrical connection with the electronic processing device. The torque generating device may be a turbine.

The piston may be disposed circumferentially around the shaft such that the shaft and piston share a slidable connection. The shaft may be rotationally connected to the jack element through a spline connection. The jack element may comprise an angled portion disposed on an indenting end of the jack element. The shaft may be substantially collinear with the axis of rotation. The porting assembly may divert a fluid flow to a first piston end or a second piston end. The electronic processing device may be in electrical communication with a direction and inclination tool. The electronic processing device may be part of a downhole telemetry network.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional diagram of an embodiment of a tool string suspended in a borehole.

FIG. 2 is a cross-sectional diagram of an embodiment of a tool string component.

FIG. 3 is a perspective diagram of an embodiment of a portion of a tool string component.

FIG. 4 a-b are cross-sectional diagrams of embodiments of a portion of a tool string component.

FIG. 5 a-b are perspective diagrams of embodiments of a porting assembly.

FIG. 6 is a perspective diagram of an embodiment of a spline connection on a shaft. FIG. 7 a-c are perspective diagrams of embodiments of an indenting end of a jack element.

FIG. 8 is a cross-sectional diagram of an embodiment of a cutter profile.

FIG. 9 is a cross-sectional diagram of an embodiment of a downhole tool string component.

FIG. 10 is a cross-sectional diagram of an embodiment of a downhole telemetry network.

FIG. 11 is a cross-sectional diagram of an embodiment of a piston in a downhole tool string component.

FIG. 12 is a cross-sectional diagram of another embodiment of a downhole tool string component.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 is a perspective diagram of an embodiment of a downhole tool string 100 suspended by a derrick 108 in a bore hole 102. A drilling assembly 103 is located at the bottom of the bore hole 102 and comprises a drill bit 104. As the drill bit 104 rotates downhole the downhole tool string 100 advances farther into the earth. The downhole tool string 100 may penetrate soft or hard subterranean formations 105. The drilling assembly 103 and/or downhole components may comprise data acquisition devices which may gather data. The data may be sent to the surface via a transmission system to a data swivel 106. The data swivel 106 may send the data to the surface equipment. Further, the surface equipment may send data and/or power to downhole tools, the drill bit 104 and/or the drilling assembly 103. The downhole tool string 100 may comprise a downhole tool. The downhole tool may be selected from the group consisting of drill pipe, drill collars, production pipe, and reamers. The downhole tool string 100 may be subjected to downhole drilling stresses as at least a portion of the weight of the drill string 100 is placed on the drill bit 104. Those drilling stresses may be compressive stresses, tensile stresses, and/or torque stresses propagating through portions of the drill string 100.

FIG. 2 is a cross-sectional diagram of an embodiment of a tool string component 200. The tool string component 200 may comprise a drill bit 104 comprising a jack element 202 with an indenting end 203. The indenting end 203 may comprise a plurality of inserts 204 disposed in a pattern. The jack element 202 may be in mechanical communication with a shaft 205. The jack element 202 and shaft 205 may be substantially collinear with an axis of rotation 206 of the tool string component 200. The shaft 205 may rotate the jack element 202. The shaft 205 may be disposed intermediate a gearbox 207 and the jack element 202. The gearbox 207 may be in mechanical communication with a torque generating device 208. The torque generating device 208 may be an electric motor or fluid driven turbine. The torque generating device 208 may rotate the shaft 205. The shaft 205 may be rotated in a clockwise or counter clockwise direction and at a specific rotational velocity while the tool string component 200 is rotated in the opposite direction and the same rotational velocity as the shaft 205. This rotation configuration may leave the shaft 205 and jack element 202 rotationally stationary with respect to the formation. In some instances, the shaft 205 and the tool string component 200 may rotate in the same direction. In this case, the shaft 205 and jack 202 may rotate with respect to the formation. The shaft 205 may also be in mechanical communication with a piston 210, the piston 210 circumferentially disposed around the shaft 205 and slidably connected to the shaft 205. The piston 210 may be disposed intermediate the jack element 202 and the gear box 207.

FIG. 3 is a perspective diagram of an embodiment of a drill bit 104. The jack element 202 can be seen in substantially the center of the drill bit 104 and comprising a plurality of inserts 204. The jack element 202 may comprise an angled portion adapted to bias the tool string 100 in a desired direction.

FIG. 4 a-b are cross-sectional diagrams of embodiments of a portion of a downhole tool string component 200. The piston 210 can be seen proximate the jack element 202. The piston 210 may comprise a first piston end 400 and a second piston end 401. The piston 210 may be disposed within a pressure-sealed cylinder 300. The pressure-sealed cylinder 300 may comprise at least one exhaust port 301 such that drilling fluid entering the pressure-sealed cylinder 300 may be exhausted into a borehole when needed. The pressure-sealed cylinder 300 may comprise a drilling mud under pressure such that as the drilling mud contacts the first or second end of the piston 400/401, the piston 210 may be biased. As the piston 210 is biased, the piston 210 may contact the jack element 202. The jack element 202 may then contact a formation. The drilling fluid may then be rerouted to the opposite end of the piston 202 so as to bias the piston 202 in the opposite direction. As the jack element 202 contacts the formation and retracts back into the drill bit 104, the formation may be impacted. FIG. 4 a shows the piston 210 in an extended position while FIG. 4 b shows the piston 210 in a retracted position.

The shaft 205 within the tool component 200 may be in mechanical communication with the jack element 202 through a connection. The connection may be a rotary spline. The jack element 202 may slide axially along the shaft 205. The shaft 205 may rotate the jack element 202 such that as the tool string component 200 rotates, the shaft 205 and jack element 202 rotate in an opposite direction, leaving the jack element 202 stationary in relation to the formation. An angled portion of the jack element 202 may guide the drill bit 104 along a direction within the formation.

FIG. 5 a-b are perspective diagrams of embodiments of a porting assembly 550. The porting assembly 550 may comprise a first and a second disc 298/299. During operation, the first disc and the second disc 298/299 may be placed one on top of the other and adapted to rotate. The first and second disc 298/299 may also comprise a plurality of holes 292 such that as the porting assembly 550 is rotated, the plurality of holes 292 align and misalign. The porting assembly may be in fluid communication with a fluid flow within the tool string 100. As the plurality of holes align and misalign, the fluid flow may be diverted to one or another channel leading to an end of the piston chamber. As the flow reaches an end of the chamber, the piston may be forced to move.

FIG. 6 is a perspective diagram of an embodiment of a rotary spline connection 422 on a shaft 205. The rotary spline 422 may be adapted to mechanically connect with a jack 202. As the jack 202 is forced towards the formation by the piston 210 (shown in FIG. 4 a) the jack 202 may move along the rotary spline 422 while continuing to rotate from the force of the shaft 205 on the rotary spline 422. In this way, the jack 202 may move axially to impact the formation while simultaneously rotating axially.

FIG. 7 a-c are perspective diagrams of embodiments of an indenting end of a jack element 202 that disclose possible cutter insert arrangements. Generally, the cutter inserts may be brazed or press-fit into the indenting end of the jack element 202. The degrading end may comprise an angled portion adapted to bias the jack element 202 in a specific direction. In the case of FIG. 7 a, the cutting inserts are disposed primarily on one side of the indenting end whereas in FIG. 7 c, the cutting inserts are disposed substantially evenly on the indenting end. The plurality of inserts may include a central insert disposed substantially in the center of the indenting end and inserts surrounding the central insert. FIG. 7 c shows a plurality of inserts on an indenting end. In this embodiment, as least one of the circumferentially spaced inserts comprises a portion 625 ground with a radius that may substantially match a radius of the jack element 202 and be disposed collinearly with an outer circumference of the jack element 202. The central axis of the circumferentially spaced inserts may be non-collinear with the central axis of the jack element 202. Tilting the central axis of the inserts may expand a cutting diameter determined by the distance from the center of the jack element to the point of a cutting insert. As the cutting insert is tilted, the distance between the center of the jack element and the point of the cutting insert may increase. FIG. 7 b shows a plurality of cutting inserts disposed on the outer circumference of the indenting end of the jack element. One of the plurality of cutting inserts may be disposed on an angled surface of the jack element. As the jack element 202 is forced into the formation, the angle on the jack element 202 may bias the direction of travel of the jack element 202 within the formation. Mounting an insert on the angled portion of the jack element 202 may increase the life of the indenting end and aid in the degradation of the formation.

FIG. 8 is a cross-sectional diagram of an embodiment of a cutter profile 444 on a jack 202. The jack 202 may comprise a plurality of inserts 204. The inserts 204 may be attached to the jack 202 through a braze. The inserts 204 may also be attached to the jack 202 through a press fit. The inserts 204 may be substantially evenly spaced such that as the jack 204 contacts the formation, the formation may evenly be degraded and/or an equal portion of the formation may be contacted. As can be seen, the cutter profile 444 may include inserts 204 which overlap. Thus, the space between inserts 204 may vary leading to more closely spaced or more distantly spaced inserts 204. The inserts 204 may be placed on the jack 202 such that their central axis 488 is as much as 25 degrees away from vertical with reference to the axis of rotation 206 of the jack 202.

FIG. 9 is a cross-sectional diagram on an embodiment of a portion of a downhole tool string 100. The downhole tool string 100 may comprise a Direction and Inclination package which will be herein referred to as D & I. The D & I may be in electrical communication with an electronic processing device 330 disposed on the tool string 100. The D & I may evaluate the orientation of the tool string 100 in relation to the Earth or other standard. The electronic processing device 330 may also be in electrical communication with a position sensor 331 disposed on or adjacent to the shaft 205. The position sensor 331 may send the electronic processing device 330 signals relating to the position of the shaft 205, and thus, the position of the jack 202. Electrical line 384 displays a connection between the position sensor 331 and electronic processing device 330. Also, a generator 385 may be electrically connected to the electronic processing device 331 such that all incoming signals may be processed for use by a drilling operator or for other purposes.

FIG. 10 discloses a downhole network 717 that may be used to transmit information along a tool string 100. The network 717 may include multiple nodes 718 a-e spaced up and down a tool string 100. The nodes 718 a-e may be intelligent computing devices 718 a-e, or may be less intelligent connection devices, such as hubs or switches located along the length of the network 717. Each of the nodes 718 may or may not be addressed on the network 717. A node 718 e may be located to interface with a bottom hole assembly 103 located at the end of the tool string 100. A bottom hole assembly 103 may include a drill bit, drill collar, and other downhole tools and sensors designed to gather data and perform various tasks.

As signals from downhole tools are obtained, they may be transmitted uphole or downhole using the downhole network 717. This may assist downhole tools in communicating with each other. The downhole network 717 may be in electrical communication with an uphole computing device 728. The electronic processing device 331 and D&I may be in electrical communication with the downhole network 717.

Transmitting the jack element's orientation signal to the surface may allow drillers to make real time decisions and correct drill string trajectories that are off of the desired path before trajectory correction. In some embodiments, the signal may be transmitted wirelessly to off site locations once the signal is at the surface. Such an embodiment would allow drilling experts to position themselves in a central location and monitor multiple wells at once.

FIG. 11 displays a cross-sectional diagram of an embodiment of a portion of a tool string component 100. The shaft 205 within the tool string component 100 may comprise a super hard material 230 disposed on an outer diameter of the shaft 205 may provide an increase in wear resistance. The piston 210 may also comprise a super hard material 239. Additionally, the piston 210 may comprise a super hard material 800 disposed on a contact end of the piston 210 adjacent to the jack 202 and the jack 202 may comprise a super hard material 801 adjacent the piston 210 such that as the piston 210 contacts the jack 202, the super hard material from the piston 210 contacts the super hard material from the jack 202 contact each other.

FIG. 12 discloses a cross-sectional diagram of another embodiment of a portion of a tool string 100. The tool string 100 may comprise a shaft 205 comprising tabs 269. As the shaft 205 rotates, the tabs 269 rotate as well, contacting a multi-way valve 293. The first time the multi-way valve 293 is contacted, it may be actuated to allow a fluid flow into a channel leading to a first piston end 400. As the multi-way valve is actuated again, it may allow the fluid flow into a different channel leading to the second piston end 401.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention. 

1. A tool string component, comprising: an axis of rotation and a drill bit body intermediate a threaded end and a working face; the drill bit body housing a jack element protruding from the working face; a shaft rotationally connected and intermediate the jack element and a torque generating device; and a torque generating device connected to a porting assembly that causes a piston disposed around the shaft to move the jack element along a central axis of the shaft and independently of the drill bit body.
 2. The tool string component of claim 1, wherein the piston comprises a friction resistant surface disposed on an inner diameter.
 3. The tool string component of claim 1, wherein the piston is disposed within a substantially pressure-sealed cylinder.
 4. The tool string component of claim 3, wherein the pressure-sealed cylinder comprises a first and second exhaust port such that a fluid within the pressure-sealed cylinder may be evacuated.
 5. The tool string component of claim 3, wherein the pressure-sealed cylinder comprises a friction resistant surface.
 6. The tool string component of claim 1, wherein the shaft comprises a friction resistant surface disposed on at least a portion of an outer diameter.
 7. The tool string component of claim 1, wherein the porting assembly comprises a first and a second rotatable disk comprising a plurality of holes which when rotated, may allow a drilling fluid to pass through the plurality of holes.
 8. The tool string component of claim 1, wherein the porting assembly comprises a multi-way valve which regulates the flow of a drilling fluid.
 9. The tool string component of claim 1, wherein the porting assembly is in mechanical communication with the shaft such that the porting assembly may be rotated by the shaft.
 10. The tool string component of claim 1, wherein the torque generating device is a generator.
 11. The tool string component of claim 10, wherein the generator comprises a signal sent to an electronic processing device disposed within the component.
 12. The tool string component of claim 11, wherein a position feedback sensor is disposed within the component and in electrical connection with the electronic processing device.
 13. The tool string component of claim 1, wherein the torque generating device is a turbine.
 14. The tool string component of claim 1, wherein the piston is disposed circumferentially around the shaft such that the shaft and piston share a slidable connection.
 15. The tool string component of claim 1, wherein the shaft is rotationally connected to the jack element through a spline connection.
 16. The tool string component of claim 1, wherein the jack element comprises an angled portion disposed on an indenting end of the jack element.
 17. The tool string component of claim 1, wherein the shaft is substantially collinear with the axis of rotation.
 18. The tool string component of claim 1, wherein the porting assembly diverts a fluid flow to a first piston end or a second piston end.
 19. The tool string component of claim 18, wherein the electronic processing device is in electrical communication with a direction and inclination tool.
 20. The tool string component of claim 1, wherein the electronic processing device is part of a downhole telemetry network. 